1. Field of the Invention
The present invention generally relates to a driving device, in particular, to a fluorescent tube driving device.
2. Description of Related Art
A fluorescent tube has advantages of having a low operation temperature, a high light emitting efficiency, a long operating life, and various colors, so as to be widely applied to current illumination devices. An inverter is a core circuit driving the fluorescent tube, and common circuit architecture includes a push-pull inverter, a full-bridge inverter, and a half-bridge inverter etc. The half-bridge inverter has advantages of having simple architecture and a low cost, so that a fluorescent tube driving device mostly adopts circuit architecture being mainly the half-bridge inverter.
The half-bridge inverter achieves a high voltage and current stabilizing effect required during lighting in a resonant manner, and includes a controller, an on-off unit, and a resonant slot. During operation, the controller generates a corresponding pulse width modulation signal according to whether the fluorescent tube is lighted up, so as to control a conduction state of the on-off unit. In addition, the on-off unit may receive a DC voltage, and with switching of the conduction state of the on-off unit, an electrical power transmitted to the resonant slot by the DC voltage may be controlled. Therefore, the resonant slot generates a corresponding driving voltage, so as to drive the fluorescent tube.
However, during actual application, when a system supplies power to the controller at the first time, the controller may not light up the fluorescent tube at first time, so that electronic elements in the device may be overheating or burnt. Therefore, it is a topic to be solved in the design of the fluorescent tube driving device how to ensure that the controller may light up the fluorescent tube at first time.